Rei Saiga

Rei Saiga (斎賀 玲), also known as Psyger-0 (サイガー0, Saigā Zero).

One of Shangri-La’s top players. She earned the title “Maximum Firepower” by achieving the highest burst damage in the game. Her in-game avatar is a man covered head-to-toe in legendary equipment, but in the real world she’s a pretty teenage girl who has a crush on Sunraku.

Trivia
She is head over heels for Sunraku. In manga chapter 82, she asks him to call her by the name Rei. Sunraku still thinks she is a man.